Hard disk unit system used as external storage having conversion unit which is attachable and detachable from hard disk unit

ABSTRACT

A portable external hard disk system is provided. The hard disk system includes a hard disk unit and a conversion unit that is attachable to and detachable from the hard disk unit. The hard disk unit has an IDE interface terminal. The conversion unit has an IDE interface terminal and a USB terminal. Also, the conversion unit includes therein a secondary battery. The conversion unit supplies the combined power of the power of a USB power line and the power of the secondary battery to the hard disk unit.

CROSS REFERENCE TO RELATED APPLICATIONS

The present document claims priority to Japanese Priority Document JP2003-002664, filed in the Japanese Patent Office on Jan. 8, 2003, theentire contents of which are incorporated herein by reference to theextent permitted by law.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a hard disk system that is used asexternal storage, for example, for a personal computer and the like.

2. Description of Related Art

A hard disk drive (hereafter referred to as HDD) can store therein alarge quantity of data and enables high speed access to the stored data.For this reason, in an information processing apparatus such as apersonal computer and the like, the HDD plays an important role as anexternal storage apparatus. These days, taking advantage of such meritsof HDDs, the HDD is beginning to be used as a bulk storage apparatus forstoring image data, music data and the like even in such fields as AVdevices and the like.

Conventionally, information processing apparatuses use built-in HDDs,external HDDs that are connected through a connection cable to the bodyof the apparatus, and the like. Recently, as more information processingapparatuses have become mobile, portable HDDs that can be carried freelyhave been proposed (for example, refer to patent document 1).

In addition, among such portable HDDs, those commonly referred to asportable hard disks are already being sold. Specifically, in such aportable hard disk, the connection between a host device is made aninterface that complies with the USB (Universal Serial Bus) standard.Thus, in this portable hard disk, an AC adapter is unnecessary and powercan be supplied through the power line of the USB interface. Also, thisportable hard disk is designed such that data can be easily written andread simply by connecting it to the host device with a connection cable,without configuring a driver.

[Patent Document 1]

Japanese Patent Publication (KOKOKU) No. Hei-6-66111

SUMMARY OF THE INVENTION

The portable HDD described in patent document 1 mentioned above is notnecessarily easy to handle since the host device and the portable HDDmust be connected to each other through a dedicated connection cable. Inother words, although this portable HDD itself can be carried easily,there arises the problem of always having to carry such a dedicatedconnection cable around.

On the other hand, the above-mentioned portable hard disk can beconnected to a host device with a general purpose connection cable.However, for example, if the interface on the HDD side complies with theIDE (Integrated Device Electronics) standard, interface conversionbecomes necessary for the interface on the host device side that iscompliant with the USB standard. For this reason, the above-mentionedportable hard disk has, on its circuit board, an interface conversioncircuit (IDE/USB conversion circuit) for carrying out interfaceconversion between the interface on the HDD side (IDE) and the interfaceon the host device side (USB).

Thus, the above-mentioned portable hard disk must be designed so as tobe bigger by a margin corresponding to the size of this circuit board,thereby causing the apparatus as a whole to become larger. Also, thisportable hard disk itself has an interface that complies with the USBstandard. However, for an electronic device having an interface thatcomplies with some standard other than USB, it is necessary to prepare aportable hard disk having an interface conversion circuit for theinterface that the electronic device has.

In addition, the power supply from the above-mentioned USB interface isabout 500 mA. The portable hard disk requires more power the greater thecapacity of the HDD is. Thus, there may be cases where the performanceof the HDD must be dropped in accordance with the power which can besupplied. Such a drop in the performance of the portable hard diskcauses not only a drop in performance on the host device side but alsomay cause unstable operations of the HDD and data storage may sometimesbe impossible.

The present invention addresses the above-mentioned problems.Accordingly, there is provided a hard disk system of which an HDD of ahigh capacity can be carried freely and is easy to use.

A hard disk system related to an embodiment of the present invention isa hard disk system that is used as an external storage apparatus for ahost device and includes a hard disk unit and a conversion unit which isattachable and detachable with respect to the hard disk unit.

The hard disk unit has: a hard disk for magnetically storing data; arecording/reading section for recording and reading data to and from thehard disk; and a hard disk side interface section for inputting andoutputting the data, which is recorded to and read from the hard disk,with respect to the conversion unit through a first transfer format.

The conversion unit has: a host interface section for transmitting andreceiving data, which is recorded to and read from the hard disk, to andfrom the host device through a second transfer format; a conversion unitside interface section for inputting and outputting data, which isrecorded on and read from the hard disk, with the hard disk unit throughthe first transfer format; a transfer format conversion section forcarrying out transfer format conversion between the first transferformat and the second transfer format, and carrying out data transferbetween the host interface section and the conversion unit sideinterface section; and a power source section.

In the above-mentioned hard disk system, when the hard disk unit and theconversion unit are connected, the hard disk side interface section andthe conversion unit side interface section carry out data transferbetween each other. Also, the power source section supplies power toeach section of the conversion unit when the hard disk unit and theconversion unit are connected.

A hard disk system related to an embodiment of the present invention isa hard disk system that is used as an external storage apparatus for ahost device and includes a hard disk unit and a conversion unit which isattachable and detachable with respect to the hard disk unit.

The hard disk unit has: a hard disk for magnetically storing data; arecording/reading section for recording and reading data on and from thehard disk; and a hard disk side interface section for inputting andoutputting data, which is recorded on and read from the hard disk, withthe conversion unit through a first transfer format.

The conversion unit has: a host interface section for transmitting andreceiving data, which is recorded on and read from the hard disk, to andfrom the host device through a second transfer format; a conversion unitside interface section for inputting and outputting data, which isrecorded on and read from the hard disk, with the hard disk unit throughthe first transfer format; a transfer format conversion section forcarrying out transfer format conversion between the first transferformat and the second transfer format, and carrying out data transferbetween the host interface section and the conversion unit sideinterface section; a power source section; and a secondary battery.

In the above-mentioned hard disk system, when the hard disk unit and theconversion unit are connected, the hard disk side interface section andthe conversion unit side interface section carry out data transferbetween each other. Also, when the hard disk unit and the conversionunit are connected, the power source section supplies the combined powerof the power of a power supply line of the host interface section andthe power of the secondary battery to the hard disk unit.

In a hard disk system related to the present invention, powerconsumption is sought to be reduced, and operation is begun when thehard disk unit and the conversion unit are securely connected.

In addition, in a hard disk system related to the present invention,operative power can be secured without having to provide powerexternally, thereby making it easier to carry.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a PHD (Portable Hard Disk) unit andan adapter in use and constituting a PHD system to which the presentinvention is applied;

FIG. 2 is a perspective view showing a PHD unit and a cradle in use andconstituting a PHD system to which the present invention is applied;

FIG. 3 is a perspective view showing the configuration of a PHD unit andan adapter;

FIG. 4 is an exploded perspective view showing the configuration of aPHD unit and an adapter;

FIG. 5A and FIG. 5B are perspective views showing the configuration of ahard disk drive;

FIG. 6 is a perspective view showing how a hard disk drive isaccommodated in a first housing;

FIG. 7 is a perspective view of a main portion showing how a firstconnector is attached to a first housing;

FIG. 8 is an electrical inner configuration view of a PHD unit;

FIG. 9 is a perspective view showing the configuration of an adapter;

FIG. 10 is a plan view of a main portion of an adapter showing itsattachment structure;

FIG. 11 is an electrical inner configuration view of an adapter;

FIG. 12 is a plan view showing a PHD unit and an adapter as attached;

FIG. 13 is a perspective view showing the configuration of a PHD unitand a cradle;

FIG. 14 is an exploded perspective view showing the configuration of acradle;

FIG. 15 is a perspective view showing the configuration of a lockmechanism and an unlocking mechanism;

FIG. 16 is a perspective view showing a switch being operated by theunlocking mechanism;

FIG. 17 is a perspective view showing a condition where the lockmechanism has been released by the unlocking mechanism; and

FIG. 18 is an electrical inner configuration view of a cradle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A hard disk system, a hard disk unit and a conversion unit to which thepresent invention is applied will be described below with reference tothe attached drawings.

A hard disk system to which the present invention is applied is aportable hard disk system (hereafter referred to as a PHD system) thatis provided with, as shown in FIGS. 1 and 2: a portable hard disk unit(hereafter referred to as a PHD unit) 1: and an adapter 2 or a cradle 3serving as a conversion unit.

More specifically, in the PHD system shown in FIG. 1, the PHD unit 1 iselectrically connected to, for example, a notebook personal computer 4serving as a host device via a connection cable 5 in a state where theadapter 2 is attached to the PHD unit 1. Thus, data is written and readbetween the PHD unit 1 and the host device 4.

On the other hand, in the PHD system shown in FIG. 2, the PHD unit 1 iselectrically connected to, for example, a desktop personal computer 6serving as a host device through a connection cable 7 in a state wherethe PHD unit 1 is mounted on the cradle 3. Thus, data is written andread between the PHD unit 1 and the host device 6.

The PHD system shown in FIG. 1 is an embodiment that is suitable forhandling data between a portable host device that can be used outdoors.The PHD system shown in FIG. 2 is an embodiment that is suitable forhandling data between a desktop host device that is used mostly indoors.Thus, in the above-mentioned PHD system, it is possible to easily alterthe combination of the PHD unit 1 and the adapter 2 or the cradle 3,depending on how the system is used.

First, the PHD unit 1 of the PHD system shown in FIGS. 1 and 2 will bedescribed below.

As shown in FIGS. 3, 4 and 5, the PHD unit 1 is provided with: a firsthousing 8; a hard disk drive (hereafter referred to as HDD) 9 serving asa recording/reading section accommodated in this first housing 8; afirst connector 10 that is electrically connected to this HDD 9 andfaces outside from the first housing 8; a plurality of cushioningmembers 11 placed between the first housing 8 and the HDD 9; and a pairof upper and lower electro-magnetic shielding plates 12 for shieldingthe HDD 9.

The first housing 8 is a plastic case formed of a resin material throughinjection molding, and it has a structure in which an upper half 8 a anda lower half 8 b, each having the shape of an approximately flat box,are joined and integrated with a plurality of screws 13 into a singleunit in a condition where the upper and lower halves 8 a and 8 b aremade to face each other at their respective side walls. A space in whichthe HDD 9 is to be accommodated is formed inside this first housing 8,and the shape thereof resembles an approximately rectangular platecorresponding to the HDD 9.

Also, one of the shorter sides of the first housing 8 forms a connectionplane 8 c to be connected to the adapter 2 and the cradle 3, which willbe described later. An engagement recess 14 with which engagementprotrusions of the adapter 2 and the cradle 3 described later areengaged is formed in an approximately central position of thisconnection plane 8 c. Also, an opening 15 through which the firstconnector 10 is exposed outward is formed on the bottom surface of thisengagement recess 14.

On this connection plane 8 c, a positioning hole 16 serving as a firstpositioning section is formed on one side, and a fixing plate 17 servingas a first fixing section is provided on the other side with the firstconnector 10 between the positioning hole 16 and the fixing plate 17.The positioning hole 16 is formed so as to lead to an internal space inone corner separated from the space in the first housing 8 in which theHDD 9 is accommodated. The fixing plate 17 is positioned and fixed in aninternal space in another corner separated from the space in the firsthousing 8 in which the HDD 9 is accommodated. Then, a screw hole 17 a isformed in this fixing plate 17 in alignment with a hole formed in thefirst housing 8.

In addition, a first displaying section 18 for classifying anddisplaying the storage capacity of the HDD 9 by text or color is formedon the principal surface of the upper half 8 a. This first displayingsection 18 is devised so as to conceal gate marks generated when thefirst housing 8 is injection molded. In other words, on the upper half 8a of the first housing 8, a gate mark is generated approximately in acenter portion towards the connection plane 8 c. However, by forming thefirst displaying section 18 at such a position that this gate mark wouldbe covered, the design is improved. In addition, this first displayingsection 18 is formed in a substantially linear manner from where thisgate mark is formed towards the end on the side of the connection plane8 c.

On the other hand, an engagement recess section 19 for maintaining astate where the PHD unit 1 is mounted on a mounting section 60 of thecradle 3, which will be described later, is formed on the principalsurface of the lower half 8 b. This engagement recess section 19 isformed in the shape of an approximate rectangle of a predetermined depthand at a position on the lower half 8 b facing an engagement protrusion73 b of the cradle 3.

In addition, a pair of guide grooves 20 (first guiding sections), whichguides the PHD unit 1 in mounting it on the mounting section 60 of thecradle 3, is formed on the elongate sides of the lower half 8 b. Eachguide groove 20 of the pair is formed from the end section on the sideof the connection plane 8 c of the lower half 8 b up to some point inthe middle towards the other end. Moreover, a plurality of rubber pads21 serving as slip stoppers are provided on the principal surface of thelower half 8 b in its corner sections.

As shown in FIGS. 5A and 5B, within a space formed by a chassis 22 and atop cover 23, the HDD 9 has: a hard disk 24 that is a magnetic disk; aspindle motor 25 serving as a rotating means for rotating this hard disk24; a magnetic head 26 for recording and reading data on and from thehard disk 24; and a head actuator 27 serving as a head actuating meansfor actuating the magnetic head 26 in the radial direction of the harddisk 24 by supporting the magnetic head 26 at its tip and being movedwith its base end as a fulcrum. Also, on the back side of the chassis 22of the HDD 9 is attached a circuit board 28 including a control circuitfor controlling the above-mentioned mechanisms and for controlling therecording and reproducing by the magnetic head 26 with respect to thehard disk 24. In addition, connector pins 29 serving as an interface ofthe HDD 9, which for example complies with the IDE standard, areattached to this circuit board 28 in such a way that they face outwardfrom one of the shorter sides of the chassis 22.

As shown in FIGS. 6 and 7, the first connector 10 is a male connector,which matches the signal pin arrangement of the above-mentionedinterface of the HDD 9 that complies with the above-mentioned IDEstandard but is made smaller. This first connector 10 is attached withinthe plane of the opening 15 of the above-mentioned first housing 8 withsome allowance for movement, in other words, in a semi-fixed state.Specifically, this first connector 10 has an engagement groove 30 withwhich portions constituting the opening 15 of the above-mentioned upperhalf 8 a and lower half 8 b are engaged, and this engagement groove 30is formed over the periphery of the first connector 10. By having theportions of the upper and lower halves 8 a and 8 b that constitute theopening 15 be engaged with the engagement groove 30, this firstconnector 10 is held in a state where it is semi-engaged with theopening 15 of the first housing 8 in which the upper half 8 a and thelower half 8 b face each other. Thus, this first connector 10 can bemoved slightly within the plane of the opening 15 of the first housing8.

This first connector 10 is electrically connected to the connector pins29 of the HDD 9 through a flexible cable 31. This flexible cable 31 isshaped such that it tapers as it approaches the first connector 10 fromthe connector pins 29, and it is placed so as to be in the shape of anapproximate inverted U between the connector pins 29 and the firstconnector 10. Thus, the first connector 10 is biased outward from thefirst housing 8 by the elastic force of this flexible cable 31.Consequently, it is possible to suppress unsteadiness in connecting thefirst connector 10 to second connectors 43 and 46 of the adapter 2 andthe cradle 3, which will be described later, thereby improving thereliability of the connection between the first connector 10 and thesecond connectors 43 and 64.

The cushioning members 11 are so placed as to be engaged with the fourcorners of the HDD 9. Thus, when this HDD 9 is accommodated in the firsthousing 8, they can absorb shock, vibration and the like from outside,thereby preventing the occurrence of damage and the like to the HDD 9,while also enabling stable recording and reading of data. For thecushioning members 11, it is possible to use a visco-elastic materialsuch as rubber having elasticity, a gel substance and the like, and insome cases a metal spring such as a coil spring, a plate spring and thelike may also be used.

The pair of upper and lower electro-magnetic shielding plates 12 is madeof approximately rectangular metal plates that match the shape of theHDD 9. They shield both principal surfaces of the HDD 9, while alsoshielding the sides of this HDD 9 with a plurality of bent pieces 32bent along the sides of the HDD 9 except for the side of the HDD 9 fromwhich the above-mentioned connector pins 29 are exposed, wherein thebent pieces 32 of the upper and lower electro-magnetic shielding platesoverlap each other. Consequently, electro-magnetic waves radiated fromthe HDD 9 can be shielded appropriately inside the first housing 8.Also, in the pair of upper and lower electro-magnetic shielding plates12, a plurality of slits 32 a is formed in the bent pieces 32. Thus, theconnective condition of the bent pieces 32 with one another can beimproved, and the shielding effect with respect to electro-magneticwaves can be improved.

The first housing 8 can be made lighter by using a plastic case formedby injection molding a resin material. Moreover, a conductive layercomposed of a conductive film or the like may be formed on at least oneof the principal surface of each of the upper half 8 a and the lowerhalf 8 b facing the electro-magnetic shielding plates 12 and theprincipal surface on the side opposite that principal surface. Thismakes it possible to further improve the shielding effect forelectro-magnetic waves. Alternatively, the first housing 8 may be formedby injection molding a resin material in which a conductive filler iscontained. In this case, it is possible to improve the shielding effectfor the electro-magnetic waves without having to provide an additionalcomponent.

The electrical configuration of the PHD unit 1 will be described below.

As shown in FIG. 8, the PHD unit 1 is provided with: the hard disk 24 onwhich data is magnetically recorded as mentioned above; the spindlemotor 25 for rotationally driving this hard disk 24; the magnetic head26 for writing and reading data on and from the hard disk 24; and thehead actuator 27, to which the magnetic head 26 is attached at its tipend, that turns with its base end as a fulcrum.

The spindle motor 25 rotates the hard disk 24. The magnetic head 26 ismoved in the radial direction on the circular principal surface of thehard disk 24 by the head actuator 27, thereby carrying out magneticrecording and magnetic reading of data on and from a desired position onthe rotating hard disk 24.

In addition, the PHD unit 1 includes: a head amplifier circuit 101 fordriving the magnetic head 26 and detecting signals; a read/write circuit102 for carrying out record data processing and read data processing; anIDE interface (I/F) circuit 103 for transmitting and receiving IDEformat data; a servo circuit 104 for carrying out servo controlprocessing; and a system controller 105.

At the time of recording, the head amplifier circuit 101 amplifiesrecord data received from the read/write circuit 102 to generate writesignals, and drives the magnetic head 26 based on of these writesignals. At the time of recording, the magnetic head 26 is driven by thewrite signal, thereby generating a magnetic field corresponding to thewrite signal and records data on the hard disk 24. In addition, at thetime of reading, the magnetic head 26 detects the magnetic fieldrecorded on the hard disk 24, and generates a read signal correspondingto that magnetic field. At the time of reading, the head amplifiercircuit 101 receives the read signal generated by the magnetic head 26,performs an amplifying process, a binarizing process and the like on theread signal, and generates read data, and then supplies the read data tothe read/write circuit 102.

At the time of recording, the read/write circuit 102 performs variousrecord data processing with respect to the record data inputted from theIDE interface circuit 103, such as a process of adding an errorcorrection code, modulation processing and the like, and supplies therecord data to the head amplifier circuit 101. At the time of reading,the read/write circuit 102 performs various read data processing withrespect to the read data inputted from the head amplifier circuit 101,such as demodulation processing, an error correcting process and thelike, and supplies to the IDE interface circuit 103 the read data onwhich the above-mentioned read data processing has been performed.

At the time of recording, the IDE interface circuit 103 receives IDEdata from the adapter 2 or the cradle 3 via the first connector 10,converts the received IDE data into record data, and supplies it to theread/write circuit 102. At the time of reading, the IDE interfacecircuit 103 receives read data from the read/write circuit 102, convertsthis read data into IDE data, and outputs it to the adapter 2 or thecradle 3 via the first connector 10. Also, the IDE interface circuit 103supplies control information transferred from the adapter 2 or thecradle 3 in the IDE format to the system controller 105, and transferscontrol information supplied from the system controller 105 to theadapter 2 or the cradle 3 in the IDE format.

The servo circuit 104 carries out rotational drive control for thespindle motor 25 and actuation control for the head actuator 27 based onan error signal detected by the head amplifier circuit 101 and the likeand on position control information given by the system controller 105and the like, and records and reads data on and from a predeterminedposition on the hard disk 24.

The system controller 105 controls the servo circuit 104 and the likebased on read data and record data of the read/write circuit 102 and thevarious control information from the host devices 4 and 6 supplied viathe IDE interface circuit 103.

In addition, a jumper cable 106 is provided in the PHD unit 1. First andsecond USB power source pins 107 and 108, which are not required of anIDE interface bus, together with a transmission line which is requiredof an IDE interface bus, are provided in the first connector 10. Thejumper cable 106 is a connection line for electrically short-circuitingthe first USB power source pin 107 and the second USB power source pin108. When the adapter 2 or the cradle 3 is connected, the jumper cable106 functions as a power switch. Its function will be described later indetail.

In the PHD unit 1 having the above-mentioned configuration, the recorddata transferred from the host devices 4 and 6 can be written on thehard disk 24, and data thus written can be stored. Also, in the PHD unit1, the data stored in the hard disk 24 can be read out and transferredto the host devices 4 and 6. Thus, the PHD unit 1 functions as anexternal storage apparatus for the host devices 4 and 6.

The adapter 2, which, together with the PHD unit 1 mentioned above,forms part of the PHD system shown in FIG. 1, will be described below.

As shown in FIGS. 3, 4 and 9, the adapter 2 has: a second housing 40; abattery 41 and a circuit board 42 which are accommodated in the secondhousing 40; a second connector 43, a USB connector 44 and a power jack45 which are mounted on the circuit board 42 and face outward from thesecond housing 40; and a pair of upper and lower electro-magneticshielding plates 46 for shielding the circuit board 42.

The second housing 40 is a plastic case formed by injection molding aresin material, and it has a structure where an upper half 40 a and alower half 40 b, each having the shape of an approximately flat box, arejoined and integrated into a single unit with a plurality of screws 47,in a state where the upper and lower halves 40 a and 40 b are made toface each other at their respective side walls. A space in which thebattery 41 and the circuit board 42 are to be accommodated is formedinside this second housing 40, and the shape the second housing 40resembles an approximately rectangular plate corresponding to the firsthousing 8 so as to match the PHD unit 1 mentioned above.

Also, one of the longer sides of the second housing 40 forms aconnection plane 40 c to be connected to the above-mentioned PHD unit 1.An engagement protrusion 48 to be engaged with the engagement recess 14of the above-mentioned PHD unit 1 is formed approximately in the centerof this connection plane 40 c. Also, an opening 49 from which the secondconnector 43 faces outward is formed on the top surface of thisengagement recess 48.

Also, on this connection plane 40 c, a positioning protrusion 50 servingas a second positioning section is formed to one side of the secondconnector 43, and a screw member 51 and a protruding section 52, whichserve as a second fixing section, are formed to the other side of thesecond connector 43.

The positioning protrusion 50 is formed at a position where it would beengaged with the above-mentioned positioning hole 16 when the firstconnector 10 and the second connector 43 are connected.

As shown in FIGS. 4 and 10, the screw member 51 has a rotative operationsection 51 a that is rotationally operated and a screw section 51 b thatis screwed into the screw hole 17 a of the above-mentioned fixing plate17. The screw member 51 is rotatably accommodated in an internal spacein a corner separated from the space in which the circuit board 42 andthe battery 41 are accommodated inside the second housing 40. Also, anoperation window 53 from which the rotative operation section 51 a isexposed is formed on the lower half 40 b. Also, the screw section 51 bprotrudes outward from a hole formed in the connection plane 40 c of thesecond housing 40.

The protruding section 52 has a slanted plane 52 a of which one side istaller by a predetermined height s than the other side thereof.

In addition, a second displaying section 54 for classifying anddisplaying the interface on the side of the host device 4 by text andcolor is formed on a principal surface of the upper half 40 a. Thissecond displaying section 54 is devised so as to conceal gate marksgenerated when the second housing 40 is injection molded. In otherwords, on the upper half 40 a of the second housing 40, a gate mark isgenerated approximately in a center portion towards the connection plane40 c. However, by forming the second displaying section 54 at such aposition that this gate mark would be covered, the design is improved.In addition, this second displaying section 54 is formed in asubstantially linear manner from where this gate mark is formed towardsthe end on the side of the connection plane 40 c. Also, an LED (LightEmitting Diode) 55 for indicating a condition where the adapter 2 isconnected to the PHD unit 1, the operative condition of the PHD unit 1and the like is provided on this second displaying section 54.

The battery 41 is electrically connected to the circuit board 42 andplaced inside the second housing 40 so that one overlaps the other. Thisbattery 41 serves as an inner power source and supplies power to the PHDunit 1.

The second connector 43 mounted on the circuit board 42 is a femaleconnector corresponding to the interface on the side of the PHD unit 1that complies with the signal pin arrangement of the above-mentioned IDEstandard. This second connector 43 is attached in a state where it isengaged with the opening 49 of the above-mentioned second housing 40,that is, in a fixed condition. By being connected to the first connector10 of the PHD unit 1 mentioned above, the second connector 43 is able tosupply power to the PHD unit 1, and transmit and receive data to andfrom the PHD unit 1.

The USB connector 44 mounted on the circuit board 42 is atransmission/reception unit corresponding to the interface on the sideof the host device 4 that complies with, for example, the USB standard,and is provided so as to face outward from the side section opposite theconnection plane 40 c of the second housing 40 mentioned above. By beingconnected to the host device 4 via the connection cable 5, the USBconnector 44 is able to receive power supplied from the host device 4,and to transmit and receive data to and from the host device 4.

In addition, this circuit board 42 includes an interface conversioncircuit (IDE/USB conversion circuit) serving as an interface converterfor carrying out interface conversion between the PHD interface (IDE)and the host device 4 interface (USB) between the above-mentioned secondconnector 43 and USB connector 44. Consequently, power can be suppliedfrom the host device 4 to the PHD unit 1, and the reading and/or writingof data is made possible.

Also, the power source jack 45 mounted on the circuit board 42 isprovided such that it faces outward from the side section opposite theconnection plane 40 c of the second housing 40, and is providedalongside the above-mentioned USB connector 44. By having an AC adapterconnected to the power source jack 45, power can be supplied to the PHDunit 1 from an external power source, and the battery 41 can be charged.

In addition, this circuit board 42 includes a control circuit forcontrolling the supplying of power to the PHD unit 1 and the charging ofthe battery 41.

The pair of upper and lower electro-magnetic shielding plates 46includes approximately rectangular metal plates corresponding to theshape of the circuit board 42. They shield both principal surfaces ofthe circuit board 42 on which the second connector 43, the USB connector44 and the power source jack 45 are mounted, and are grounded inrelation to the circuit board 42. Also, the pair of upper and lowerelectro-magnetic shielding plates 46 shields this circuit board 42 in astate where a plurality of bent pieces 56 bent along the circuit board42 are bent and laid over each other. Thus, electro-magnetic wavesradiated from the circuit board 42 can be suitably shielded inside thesecond housing 40. Also, in the pair of upper and lower electro-magneticshielding plates 46, by forming a plurality of slits 56 a in the bentpieces 56 along the direction in which they are bent, the contactcondition between the respective bent pieces 56 is improved, therebymaking it possible to further improve the shielding effect forelectro-magnetic waves.

The second housing 40 can be made lighter by using a plastic case formedby injection molding a resin material. Moreover, a conductive layercomposed of a conductive film or the like may be formed on at least oneof the principal surface of each of the upper half 40 a and the lowerhalf 40 b facing the electro-magnetic shielding plates 46 and theprincipal surface on the side opposite that principal surface. Thismakes it possible to further improve the shielding effect forelectro-magnetic waves. Alternatively, the second housing 40 may beformed by injection molding a resin material in which a conductivefiller is contained. In this case, it is possible to improve theshielding effect for electro-magnetic waves without having to provide anadditional component.

The electrical configuration of the adapter 2 will be described below.

As shown in FIG. 11, the adapter 2 includes a USB interface (I/F)circuit 111, an IDE interface (I/F) circuit 112 and a USB/IDE conversioncircuit 113.

The USB interface circuit 111 is an interface circuit for transmittingand receiving data in USB format to and from the host device 4 throughthe USB connector 44. The IDE interface circuit 112 is the interfacecircuit for transmitting and receiving data in IDE format to and fromthe PHD unit 1 through the second connector 43. The USB/IDE conversioncircuit 113 is a circuit for carrying out conversion from data of USBformat into data of IDE format and vice versa.

In the adapter 2 having the above-mentioned configuration, the USBinterface circuit 111 receives data in USB format transferred from thehost device 4 through the USB connector 44. The USB interface circuit111 transfers the data in USB format received from the host device 4 tothe USB/IDE conversion circuit 113. The USB/IDE conversion circuit 113converts the data in USB format transferred from the USB interfacecircuit 111 into data in IDE format, and transfers it to the IDEinterface circuit 112. The IDE interface circuit 112 transfers the datain IDE format to the PHD unit 1 via the second connector 43. Thus, inthe adapter 2, it is possible to convert data received in USB formatfrom the host device 4 into IDE format data, transfer it to the PHD unit1, and record the data on the hard disk 24 in the PHD unit 1.

In addition, in the adapter 2, the IDE interface circuit 112 receivesdata in IDE format transferred from the PHD unit 1 through the secondconnector 43. The IDE interface circuit 112 transfers the data in IDEformat received from the PHD unit 1 to the USB/IDE conversion circuit113. The USB/IDE conversion circuit 113 converts the data in IDE formattransferred from the IDE interface circuit 112 into data in USB format,and transfers it to the USB interface circuit 111. The USB interfacecircuit 111 transmits the data in USB format to the host device 4 viathe USB connector 44. Thus, in the adapter 2, it is possible to convertdata of IDE format read from the hard disk 24 in the PHD unit 1 intodata of USB format, and transmit it to the host device 4.

In addition, the adapter 2 includes a DC/DC converter 114 for supplyingpower to the PHD unit 1.

The DC/DC converter 114 is a direct current voltage conversion circuit,such as a so-called switching converter and the like, and is capable ofgenerating a voltage stabilized at a predetermined value regardless ofthe load. A direct current voltage (VCC) outputted from the DC/DCconverter 114 is supplied as direct current power that complies with theIDE standard to the PHD unit 1 through the second connector 43 togetherwith data that is inputted and outputted through the IDE interfacecircuit 112.

The power supplied to this DC/DC converter 114 is USB power (V_USB)transmitted from the host device 4 through a power line of the USBinterface, external power (V_IN) received from an external power source(for example, a converting apparatus for converting AC power into DCpower), and battery power (V_BATT) generated by the battery 41 providedinside the adapter 2. Hereafter, the power input terminal of the DC/DCconverter 114 is referred to as input terminal A, and the circuitconfiguration around the DC/DC converter 114 will be described below.

First and second USB power source pins 115 and 116, which are notrequired of an IDE interface bus, together with pins matching thetransmission line required of an IDE interface are provided in thesecond connector 43. The first USB power source pin 115 is connected tothe USB power line, which is a power line that is USB compliant, via theUSB interface circuit 111. The second USB power source pin 116 isconnected to the input terminal A of the DC/DC converter 114 through adiode 117. The diode 117 has its cathode connected to the input terminalA, thereby preventing a reverse flow to the USB power line.

The first and second USB power source pins 115 and 116 are connected tothe first and second USB power source pins 107 and 108 on the side ofthe PHD unit 1, respectively, when the adapter 2 is connected to the PHDunit 1, that is, when the first connector 10 and the second connector 43are connected. The first and second USB power source pins 107 and 108 onthe side of the PHD unit 1 are short-circuited inside the PHD unit 1with the jumper cable 106. Thus, when the adapter 2 is connected to thePHD unit 1, the first USB power source pin 115 and the second USB powersource pin 116 are electrically connected. Thus, when the adapter 2 isconnected to the PHD unit 1 and the host device 4 and the adapter 2 areconnected through the USB cable 5, USB power (V_USB) is supplied to theDC/DC converter 114.

The power source jack 45 is connected to the input terminal A of theDC/DC converter 114 via a diode 118. The diode 118 has its cathodeconnected to the input terminal A, thereby preventing counter currentsto the external power source. Thus, when the external power source isconnected, external power (V_IN) is supplied to the DC/DC converter 114.

The battery 41 has its negative terminal grounded. The battery 41 hasits positive terminal connected to the input terminal A of the DC/DCconverter 114 via a mode switch 120, a battery switch 121 and a diode122 which are connected in series. The diode 122 has its cathodeconnected to the input terminal A. In other words, the mode switch 120and the battery switch 121 are connected in series between the anode ofthe diode 122 and the positive terminal of the battery 41. Thus, countercurrents to the battery 41 from the input terminal A is prevented.

The mode switch 120 is a switch for switching between on (closed) andoff (open) on the basis of an insertion detection signal indicatingwhether or not an output plug of the external power source is insertedinto the power source jack 45. The mode switch 120 becomes off when theoutput plug of the external power source is inserted into the powersource jack 45. The mode switch 120 becomes on when the output plug ofthe external power source is not inserted into the power source jack 45.The state where the output plug of the external power source is insertedinto the power source jack 45 is referred to as recharge mode, and thestate where the output plug of the external power source is not insertedinto the power source jack 45 is referred to as discharge mode.

The battery switch 121 switches between on (closed) and off (open) onthe basis of the state of the voltage at the input terminal A of theDC/DC converter 114 supplied through the diode 118. The battery switch121 becomes on when a voltage is applied to the input terminal A (thatis, when USB electric power (V_USB) or external electric power (V_IN) issupplied), and it becomes off when a voltage is not applied to the inputterminal A.

Thus, in discharge mode, the combined power of USB power (V_USB) andbattery power (V_BATT) is supplied to the DC/DC converter 114. Also, inrecharge mode, the combined power of external power (V_IN) and USB power(V_USB) is supplied to the DC/DC converter 114. A circuit configurationin which only external power (V_IN) is supplied to the DC/DC converter114 in recharge mode may be adopted.

One end of a charging switch 123 is connected to the positive terminalof the battery 41. The other end of the charging switch 123 is connectedto the power source jack 45 via a diode 124 and to the second USB powersource pin 116 of the second connector 43 via a diode 125. Cathodes ofthe diodes 124 and 125 are both connected to the charging switch 123,thereby preventing counter currents from the battery 41 to the externalpower source and the USB power line. The charging switch 123 switchesbetween on (closed) and off (open) on the basis of a control signal.Thus, when the charging switch 123 is on, the battery 41 is charged withUSB power (V_USB) and external power (V_IN).

In addition, the adapter 2 may have a temperature sensor 126, a capacitysensor 127 and a controller 128.

The temperature sensor 126 is a sensor for detecting the temperature ofthe battery 41. The capacity sensor 127 is a sensor for detecting thecapacity of the battery 41.

The controller 128 controls the supplying of power to the USB interfacecircuit 111, the IDE interface circuit 112, the USB/IDE conversioncircuit 113, the DC/DC converter 114 and the like, and controls thecharging switch 123, and the like. The second USB power source pin 116of the second connector 43 is connected to the controller 128. Thecontroller 128 judges the state of the voltage of this second USB powersource pin 116 and controls the supplying of power as mentioned above.Also, the controller 128 carries out drive control for the LED 55.

The power supply operation of the adapter 2 having the above-mentionedconfiguration, and the various control operations will be describedbelow.

The adapter 2 is a system that carries out switching control of powersupply by way of apparatus connection in such a way that power is notsupplied unless the host device 4 and the PHD unit 1 are securelyconnected. The controller 128 detects the voltage of the second USBpower source pin 116 of the second connector 43, and when the voltage isdetected, it controls the supplying of power to the USB interfacecircuit 111, the IDE interface circuit 112, the USB/IDE conversioncircuit 113 and the like. Through such control, the adapter 2 is made asystem that does not supply power unless the host device 4 and the PHDunit 1 are connected securely. Thus, in the adapter 2, for example, evenwhen only an external power source is connected, or a cable which shouldnot have been connected is erroneously connected, there is no risk thatunusual power related circumstances would occur. A switch for turningexternal power (V_IN) from the power source jack 45 on and off may beprovided, and such control where that switch is turned on when thevoltage of the second USB power source pin 116 is detected may beperformed.

Also, in the adapter 2, the mode switch 120 is off in recharge mode (themode in which the plug of the external power source is connected to thepower source jack 45), and external power (V_IN) and USB power (V_USB)are supplied to the PHD unit 1. Also, in recharge mode, external power(V_IN) and USB power (V_USB) are supplied to the battery 41, andrecharging is carried out. Hence, if an external power source isconnected, the battery 41 is charged without the user being consciouslyaware of it.

In addition, in the adapter 2, the mode switch 120 is on in dischargemode (the mode in which the plug of the external power source is notconnected to the power source jack 45), and the combined power of USBpower (V_USB) and battery power (V_BATT) is supplied to the PHD unit 1.Thus, even if a data transfer bus whose power line has a small powercapacity is used to carry out transmission/reception with the hostdevice 4, the shortage can be compensated for with the battery power(V_BATT) generated by the battery 41. Thus, even if an external powersource is not carried around together, this portable hard disk can beused, thereby improving its portability.

In addition, in discharge mode, USB power (V_USB) is supplied to thebattery 41. The adapter 2 supplies a stable voltage to the PHD unit 1using the DC/DC converter 114. Thus, if the drive load of the DC/DCconverter 114 is substantial (such as when the PHD unit 1 is operated),power is pulled to the DC/DC converter 114 from the battery 41. However,when the drive load of the DC/DC converter 114 is light (such as whenthe PHD unit 1 is not operating), power is not discharged from thebattery 41, and some power of the USB power (V_USB) is left over. Thus,even in discharge mode, the power of the USB electric power (V_USB) thatis left over charges the battery 41. Typically, even if an informationstorage apparatus and a computer are connected, it is not always thecase that the information storage apparatus is operating, and oftentimes the information storage apparatus is not operating. Thus, chargingcan be performed more efficiently by adopting such a circuitconfiguration where the excess power of the USB electric power (V_USB)is used to charge the battery 41 as mentioned above.

In addition, the adapter 2 carries out deterioration prevention andsafety measures for the battery 41 by controlling the power source inaccordance with the temperature of the battery 41. When the temperatureof the battery 41 detected by the temperature sensor 126 becomes equalto or greater than a first temperature, the controller 128 turns off thecharging switch 123 and terminates charging. Also, when the temperatureof the battery 41 becomes equal to or greater than a second temperature(it is preferable that the second temperature be set to a value higherthan the first temperature), the operation itself of the adapter 2 isstopped.

In addition, the adapter 2 manages the capacity of the battery 41, andprevents the PHD unit 1 from suddenly stopping operating due to thebattery 41 running out. When the capacity of the battery 41 detected bythe capacity sensor 127 becomes equal to or less than a first threshold,the controller 128 notifies the host device 4 with warning informationthrough the USB interface circuit 111. When notified with warninginformation, the host device 4, for example, may display on the screenthe fact that the battery 41 is running low, or may give an audionotification of the same fact. Also, when the capacity of the battery 41detected by the capacity sensor 127 becomes equal to or less than asecond threshold (the second threshold is a value that is smaller thanthe first threshold), the controller 128 carries out control to stop theoperation of the adapter 2 altogether. As mentioned above, by preventingthe operation from suddenly stopping due to a drop in the capacity ofthe battery 41, it is possible to prevent data from being corrupted by asudden stop in operation during the process of writing to or readingfrom the hard disk.

In addition, the adapter 2 manages the capacity of the battery 41, andwhen the battery 41 is fully charged, it turns off the charging switch123 and stops the charging operation.

In addition, when operation is stopped because the temperature of thebattery 41 is at or above the second temperature, because the capacityof the battery 41 is equal to or less than the second threshold value,or due to some other control, the controller 128, for example, watchesfor a communication flag (a flag generated when data is beingtransferred) generated by the USB/IDE conversion circuit 113, andcarries out an operation stopping process at a point when the hostdevice 4 is not writing nor reading data. The execution of such aprocess can protect data from being corrupted by having operationstopped during the process of writing to or reading from the hard disk.

In addition, the controller 128 can notify the user of the operativestatus of the adapter 2 by carrying out display control of the LED 55.For example, the controller 128 may turn on the LED 55 if the hostdevice 4 and the PHD unit 1 are connected to the adapter 2. In addition,the controller 128 may, for example, watch for a communication flag (aflag generated when data is being transferred) generated by the USB/IDEconversion circuit 113, and make the LED 55 blink if the host device 4is writing or reading data. The controller 128, for example, may alsomake the LED 55 emit different colors depending on whether the mode isthe recharge mode or the discharge mode. Moreover, information foridentifying whether the battery 41 is being recharged or is fullycharged and information for identifying the capacity of the battery 41may also be displayed.

In the PHD system that is configured in the manner described above andshown in FIG. 1, when the adapter 2 is connected to the PHD unit 1, theengagement protrusion 48 on the side of the adapter 2 is engaged withthe engagement recess 14 on the side of the PHD unit 1, and the firstconnector 10 on the side of the PHD unit 1 and the second connector 43on the side of the adapter 2 are thus connected. Then, with thepositioning protrusion 50 on the side of the adapter 2 engaged with thepositioning hole 16 on the side of the PHD unit 1 and the second housing40 positioned in relation to the first housing 8, the rotative operationsection 51 a of the screw member 51 provided on the side of the adapter2 is rotationally operated, the screw section 51 b is screwed into thescrew hole 17 a of the fixing plate 17 provided on the side of the PHDunit 1, and the second housing 40 is fixed to the first housing 8. Thus,a state where the adapter 2 is attached to the PHD unit 1 is maintained.

The first connector 10 on the side of the PHD unit 1 is attached withinthe plane of the opening 15 of the first housing 8 in a semi-fixed statewith some allowance for movement. On the other hand, the secondconnector 43 on the side of the adapter 2 is attached in a fixed statewhere it is engaged with the opening 49 of the second housing 40. Thus,in this PHD system, it is possible to suitably connect the firstconnector 10 and the second connector 43 without positioning themprecisely, and damage to the connectors upon connecting can beprevented, while the connective reliability of the first connector 10and the second connector 43 can also be improved.

In addition, in this PHD system, as shown in FIG. 12, the protrudingsection 52 formed on the connection plane 40 c where the secondconnector 43 of the adapter 2 faces outward is brought into contact withthe connection plane 8 c from which the first connector 10 of the PHDunit 1 faces outward. Thus, the second housing 40 is at a slight anglewith respect to the first housing 8 such that one side of each of theconnection planes 8 c and 40 c are closer to each other and the otherside of each of the connection planes 8 c and 40 c are spaced furtherapart from each other. Consequently, even if the housings 8 and 40 arefixed to one side of the connectors of the connection planes 8 c and 40c, it is possible to prevent the positioning protrusion 50 from fallingout from the positioning hole 16 formed to the other side of theconnectors of the connection planes 8 c and 40 c, and suitably maintaina state where the first housing 8 and the second housing 40 are fixed.

Thus, in this PHD system, the PHD unit 1 and the adapter 2 can beintegrated into a single unit with a simple structure without adopting astructure in which the connection planes are fixed to each other to bothsides of the first connector 10 and the second connector 43. Hence,further miniaturization can be attained.

Also, in this PHD system, as shown in FIG. 1, when the PHD unit 1 andthe adapter 2 are integrated into a single unit, the first displayingsection 18 and the second displaying section 54 form a continuous andlinear displaying section between the first housing 8 and the secondhousing 40, thereby making aesthetically superior display possible.Also, it helps to prevent the erroneous connection of the adapter 2 andthe PHD unit 1, thereby improving the ease of use.

This PHD system is electrically connected to, for example, a notebookpersonal computer 4, which is a host device, via the connection cable 5in a condition where the adapter 2 and the PHD unit 1 are connected.Thus, data is written to and read from the host device 4.

In this PHD system, since power can be supplied to the PHD unit 1 fromthe battery 41 in the adapter 2, or from an external power source byhaving the plug of an AC adapter connected to the power source jack 45,and not just from the host device 4 via the power line of a USBcompliant interface, even if the PHD unit 1 includes an HDD 9 of a highcapacity, it is possible to stabilize the driving of this PHD unit 1,and to prevent a drop in performance.

The cradle 3, which together with the above-mentioned PHD unit 1 formspart of the PHD system shown in FIG. 2, will be described below.

As shown in FIGS. 13 and 14, this cradle 3 is provided with: a secondhousing 61 including a mounting section 60 in which the PHD unit 1 isset; a first circuit board 62 and a second circuit board 63 that areaccommodated in the second housing 61; a second connector 64 that ismounted on the first circuit board 62 and faces outward from a bottomplane 60 a of the mounting section 60; a first USB connector 65, asecond USB connector 66, a third USB connector 67 and a power sourcejack 68 that are mounted on the second circuit board 63 and face outwardfrom the rear side of the second housing 61; a first pair of upper andlower electro-magnetic shielding plates 69 for shielding the firstcircuit board 62; and a second pair of upper and lower electro-magneticshielding plates 70 for shielding the second circuit board 63.

The second housing 61 has a structure where it is divided into a frontpanel 61 a, a center panel 61 b, a back panel 61 c and a bottom panel 61d. Each of the panels is formed by injection molding a resin material.Then, this second housing 61 is joined and integrated with a pluralityof screws (not shown) while they are fitted with one another.

The mounting section 60 is comprised of the front panel 61 a and thecenter panel 61 b. A concave section corresponding in shape to the firsthousing 8 is formed so that the PHD unit 1 fits nicely. An engagementprotrusion 60 e, which engages with the engagement recess 14 of the PHDunit 1 mentioned above, is formed on the bottom plane 60 a of thismounting section 60. Also, an opening 71 from which the second connector64 faces outward is formed on the inner side of this engagementprotrusion 60 e, and the second connector 64 is attached such that it isengaged with this opening 71, that is, the second connector 64 is fixed.

In addition, as shown in FIGS. 14 and 15, a lock mechanism 72 formaintaining a state where the PHD unit 1 is set in this mounting section60 is formed on the rear side 60 b of the mounting section 60 forsupporting the rear side of the PHD unit 1.

As shown in FIGS. 13, 14 and 15, this lock mechanism 72 has: anengagement member 73 serving as a second engagement section that engageswith the engagement recess section 19 of the PHD unit 1 mentioned above;and a spring member 74 for biasing this engagement member 73 in thedirection in which it engages with the engagement recess section 19.

The engagement member 73 is comprised of an elongate member, and has: apair of shafts 73 a, on one end side of the elongate member, pivotallysupported by a pair of bearing sections 75 formed on the center panel 61b and the back panel 61 c; an engagement protrusion 73 b, on the otherend side of the elongate member, that is exposed from the rear side 60 bof the mounting section 60 through the opening 76 formed in the centerpanel 61 b; and, at the middle section of the elongate member, a pair ofspring support pieces 73 c onto which the spring member 74 is hooked. Byhaving the pair of shafts 73 a pivotally supported by the pair ofbearing sections 75, the engagement member 73 is so supported as to bemovable between a position where the engagement protrusion 73 b isengaged with the engagement recess section 19 b of the PHD unit 1 set inthe mounting section 60 and a position where the engagement with theengagement recess section 19 of this PHD unit 1 is undone.

The spring member 74 has the pair of shafts 73 a of the engagementmember 73 inserted into a pair of coiled sections 74 a that are formedby having a wire material coiled, and both ends 74 b of the wirematerial that are extended from this pair of coiled sections 74 a andare elastically displaceable are hooked onto the pair of spring supportpieces 73 c of the engagement member 73. This spring member 74 ispositioned under a condition where an elastically displaceable middlesection 74 c, which has a predetermined angle with respect to both ends74 b hooked onto the pair of spring support pieces 73 c of theengagement member 73, is in contact with the back panel 61 c.Consequently, the spring member 74 biases the engagement member 73 inthe direction in which the engagement protrusion 73 b is exposed fromthe rear side 60 b of the mounting section 60 through the opening 76 inthe center panel 61 b.

In addition, with this lock mechanism 72, by having the engagementprotrusion 73 b of the engagement member 73 engaged with the engagementrecess section 19 of the PHD unit 1 when the PHD unit 1 is set in themounting section 60, it is possible to maintain a state where the PHDunit 1 is set in the mounting section 60, and to prevent the PHD unit 1from being detached from the mounting section 60 during operation.

In addition, an unlocking mechanism 77 for unlocking the locked state ofthe PHD unit 1 by the above-mentioned lock mechanism 72 is provided inthe second housing 61.

This unlocking mechanism 77 has: an operation button 78 that facesoutward from one side section of the second housing 61; an operationmember 79 that is operated by pressing this operation button 78; and acompression coil spring 80 for biasing this operation member 79 in apredetermined direction so that the operation button 78 protrudes fromthe second housing 61. Moreover, the operation member 79 has: aswitching protrusion 79 a for operating a switch 81, which is formed onthe first circuit board 62 and serves as a switching means for switchingthe electrical connection between the PHD unit 1 and the host device 6;a sliding operation section 79 b that is slid and operated while inengagement with the other end side of the engagement member 73; and anarm section 79 c that links the switching protrusion 79 a and thesliding operation section 79 b.

Then, in this unlocking mechanism 77, as shown in FIG. 16, the operationbutton 78 is pushed against the biasing force of the compression coil 80so that the switching protrusion 79 a of the operation member 79operates the switch 81, thereby cutting the electrical connectionbetween the PHD unit 1 and the host device 6. Then, as shown in FIG. 17,while the sliding operation section 79 b of the operation member 79 isengaged with the other end side of the engagement member 73, theengagement protrusion 73 b of the engagement member 73 is moved in apredetermined direction so that the engagement with the engagementrecess section 19 of the PHD unit 1 set in the mounting section 60 isundone. Consequently, the locked state of the PHD unit 1 by the lockmechanism 72 mentioned above is undone. In other words, with thisunlocking mechanism 77, the electrical connection between the PHD unit 1and the host device 6 can be cut before the engagement between theengagement protrusion 73 b of the engagement member 73 and theengagement recess section 19 of the PHD unit 1 is undone by having theswitching protrusion 79 a of the operation member 79 operate the switch81.

As shown in FIG. 13, a pair of guide protrusions 82 serving as secondguide sections to be engaged with the pair of guide grooves 20 in thePHD unit 1 mentioned above is formed on both side sections 60 c of themounting section 60. The pair of guide protrusions 82 is formed alongboth of the side sections 60 c from the end on the side of the bottomplane 60 a of the mounting section 60.

In addition, a second displaying section 83 is formed on the principalsurface of the front panel 61 a. This second displaying section 83 isdevised so as to conceal gate marks generated when the front panel 61 ais injection molded. In other words, a gate mark is generated inapproximately the center of the front panel 61 a. However, by formingthe second displaying section 83 at such a position that this gate markwould be covered, the design is improved. In addition, this seconddisplaying section 83 is formed in a substantially linear manner fromwhere this gate mark is formed towards the end on the side of themounting section 60. Also, an LED (Light Emitting Diode) 84 thatindicates a state where the PHD unit 1 is mounted on the cradle 3, theoperative status of the PHD unit 1 and the like is provided on thissecond displaying section 83. Moreover, on the bottom panel 61 d, aplurality of rubber pads (not shown) serving as slip stoppers isprovided in the corner sections.

The second connector 64 mounted on the first circuit board 62 is afemale connector corresponding to the interface on the side of the PHDunit 1 that complies with the signal pin arrangement of theabove-mentioned IDE standard. By being connected to the first connector10 of the PHD unit 1 mentioned above, the second connector 64 is able tosupply power to the PHD unit 1, and transmit and receive data to andfrom the PHD unit 1.

The first USB connector 65 mounted on the second circuit board 63 is atransmission/reception unit corresponding to the interface on the sideof the host device 6 that complies with, for example, the USB standard,and it is provided so as to face outward from the rear side of the backpanel 61 c. By being connected to the host device 6 via the connectioncable 7, the first USB connector 65 is able to receive power from thehost device 6, and transmit and receive data to and from the host device6.

In addition, this second circuit board 63 includes an interfaceconversion circuit (IDE/USB conversion circuit) serving as an interfaceconverter for carrying out, between the above-mentioned second connector64 and first USB connector 65, interface conversion between theinterface on the side of the PHD unit 1 (IDE) and the interface on theside of the host device 6 (USB). Thus, power can be supplied from thehost device 6 to the PHD unit 1, and data can be written to and/or readfrom the PHD unit 1.

In addition, the second USB connector 66 and the third USB connector 67mounted on the second circuit board 63 are alternatetransmission/reception units that comply with, for example, the USBstandard, and they are provided so as to face outward from the backpanel 61 c. By being connected to an electronic device other than thehost device 6, the second USB connector 66 or the third USB connector 67is able to supply power to that electronic device, and transmit andreceive data with that electronic device.

In addition, the power source jack 68 mounted on the second circuitboard 63 is provided such that it faces outward from the rear side ofthe back panel 61 c and is alongside the above-mentioned first USBconnector 65. Also, by having the plug of an AC adapter connectedthereto, the power source jack 68 is able to supply power from theexternal power source to the PHD unit 1.

In addition, this second circuit board 63 includes a control circuit forcontrolling the supplying of power to the PHD unit 1. Thus, it ispossible to stabilize the driving of the PHD unit 1.

The first pair of upper and lower electro-magnetic shielding plates 69and the second pair of electro-magnetic shielding plates 70 are made ofapproximately rectangular metal plates corresponding in shape to thefirst circuit board 62 and the second circuit board 63. They shield bothprincipal surfaces of the first circuit board 62 and the second circuitboard 63, and are grounded in relation to the first circuit board 62 andthe second circuit board 63. Also, the first pair of upper and lowerfirst electro-magnetic shielding plates 69 and the second pair of upperand lower electro-magnetic shielding plates 70 shield the first circuitboard 62 and the second circuit board 63 in a state where a plurality ofbent pieces 85 and 86 bent along the first circuit board 62 and thesecond circuit board 63 overlap each other. Thus, electro-magnetic wavesradiated from the first circuit board 62 and the second circuit board 63can be suitably shielded inside the second housing 61. Also, the firstpair of upper and lower electro-magnetic shielding plates 69 and thesecond pair of electro-magnetic shielding plates 70 have a plurality ofslits 85 a and 86 a formed in the bent pieces 85 and 86 along thedirection in which they are bent, thereby improving contact between thebent pieces 85 and 86, and further improving the shielding effect forelectro-magnetic waves.

In addition, each of the panels of the second housing 61 can be madelighter by using plastic cases formed by injection molding a resinmaterial. Moreover, a conductive layer comprised of a conductive film orthe like may be formed on at least one of the main surface of the panelfacing the first electro-magnetic shielding plates 69 or the secondelectro-magnetic shielding plates 70 and the main surface opposite thatmain surface. This makes it possible to further improve the shieldingeffect for electro-magnetic waves. Alternatively, each of the panels ofthe second housing 61 may be formed by injection molding a resinmaterial in which a conductive filler is contained. In this case, it ispossible to improve the shielding effect for electro-magnetic waveswithout having to provide an additional component.

The electrical configuration of the cradle 3 will be described below.

The cradle 3 includes a USB hub circuit 131, an IDE interface (I/F)circuit 132 and a USB/IDE conversion circuit 133, as shown in FIG. 18.

The USB hub circuit 131 is an interface circuit for transmitting andreceiving data in USB format to and from the host device 6 via the firstUSB connector 65, the second USB connector 66 and the third USBconnector 67. The plurality of USB connectors 65 to 67 are connected tothe USB hub circuit 131, and any of the connectors may be connected tothe host device 6. Also, the USB hub circuit 131 has a so-called hubfunction. If a device other than the host device 6 is connected to oneof the first to third USB connectors 65 to 67, it mediates thetransmission and reception of data between the host device 6 and thatother device. The IDE interface circuit 132 is an interface circuit fortransmitting and receiving data in IDE format to and from the PHD unit 1through the second connector 64. The USB/IDE conversion circuit 133 is acircuit for carrying out the conversion of data in USB format into datain IDE format and vice versa.

In the cradle 3 having such a configuration, the USB hub circuit 131receives data in USB format transferred through any of the first tothird USB connectors 65 to 67 from the host device 6. The USB hubcircuit 131 transfers the data in USB format received from the hostdevice 6 to the USB/IDE conversion circuit 133. The USB/IDE conversioncircuit 133 converts the data in USB format transferred from the USB hubcircuit 131 into IDE format data, and transfers it to the IDE interfacecircuit 132. The IDE interface circuit 132 transfers the data in IDEformat to the PHD unit 1 through the second connector 64. Thus, with thecradle 3, data received in USB format from the host device 6 can beconverted into IDE format data and transferred to the PHD unit 1. Then,that data can be recorded on the hard disk 24 in the PHD unit 1.

In addition, in the cradle 3, the IDE interface circuit 132 receivesdata in IDE format transferred from the PHD unit 1 through the secondconnector 64. The IDE interface circuit 132 transfers the data in IDEformat received from the PHD unit 1 to the USB/IDE conversion circuit133. The USB/IDE conversion circuit 133 converts the data in IDE formattransferred from the IDE interface circuit 132 into data in USB format,and transfers it to the USB hub circuit 131. The USB hub circuit 131transmits the data in USB format to the host device 6 through any of thefirst to third USB connectors 65 to 67. Thus, with the cradle 3, data inIDE format read from the hard disk 24 in the PHD unit 1 can be convertedinto USB format data and transmitted to the host device 6.

In addition, the cradle 3 includes a DC/DC converter 134 for supplyingpower to the PHD unit 1.

The DC/DC converter 134 is a direct current voltage conversion circuit,such as a so-called switching converter and the like, and can generate avoltage stabilized at a predetermined value regardless of the load. Thedirect current voltage (VCC) outputted from the DC/DC converter 134 issupplied, as direct current power that is IDE compliant, to the PHD unit1 through the second connector 64 along with data that is inputted andoutputted through the IDE interface circuit 132.

The power supplied to this DC/DC converter 134 is external power (V_IN)inputted from an external power source (for example, a conversionapparatus for converting AC power into DC power). The power source jack68 is connected to an input terminal of the DC/DC converter 134 througha switch 81 and a diode 135. The diode 135 has its cathode connected tothe input terminal of the DC/DC converter 134, thereby preventingcounter currents to the external power source. Thus, when an externalpower source is connected, external power (V_IN) is supplied to theDC/DC converter 134.

In addition, the switch 81 is a switch that is turned on and off inconjunction with the unlocking mechanism 77 and cuts the supplying ofpower to the PHD unit 1. The switch 81 is turned on (closed) when thePHD unit 1 is connected to the cradle 3. However, it is turned off(opened) when the user presses the operation button 78 and removes thePHD unit 1 from the cradle 3. Moreover, this switch 81 has a mechanismwhere it is turned off before the first connector 10 and the secondconnector 64 are released. Thus, by virtue of this switch, the supplyingof power to the PHD unit 1 is always stopped before the PHD unit 1 isremoved from the cradle 3.

Along with pins corresponding to the transmission line required of anIDE interface, the second connector 64 is provided with first and secondUSB power source pins 136 and 137 not required of an IDE interface bus.The first USB power source pin 136 is connected to a USB power line,which is a power line defined in the USB standard, via the USB hubcircuit 131. The second USB power source pin 137 is connected to acontroller 138.

The first and second USB power source pins 136 and 137 are connected tothe first and second USB power source pins 107 and 108 on the side ofthe PHD unit 1, respectively, when the PHD unit 1 is mounted on thecradle 3, that is, when the first connector 10 and the second connector64 are connected. The first and second USB power source pins 107 and 108on the side of the PHD unit 1 are short-circuited by the jumper cable106 inside the PHD unit 1. Thus, when the PHD unit 1 is mounted on thecradle 3, the first USB power source pin 136 and the second USB powersource pin 137 are electrically connected. Thus, USB power (V_USB) issupplied to the DC/DC converter 134 when the PHD unit 1 is mounted onthe cradle 3 and the host device 6 and the cradle 3 are connectedthrough the USB cable 7.

The controller 138 controls the supplying of power to the USB hubcircuit 131, the IDE interface circuit 132, the USB/IDE conversioncircuit 133, the DC/DC converter 134 and the like. Also, the second USBpower source pin 137 of the second connector 64 is connected to thecontroller 138. The controller 138 judges the state of the voltage ofthis second USB power source pin 137, and carries out theabove-mentioned control of power supply. Also, the controller 138carries out drive control for the LED 84.

The power supply operation of the cradle 3 having the above-mentionedconfiguration, and the various control operations will be describedbelow.

The cradle 3 is a system in which switching control of power supply isperformed in accordance with apparatus connection where power is notsupplied unless the host device 6 and the PHD unit 1 are securelyconnected. The controller 138 detects the voltage of the second USBpower source pin 137 of the second connector 64. When the voltage isdetected, the controller 138 carries out power supply control to the USBhub circuit 131, the IDE interface circuit 132, the USB/IDE conversioncircuit 133 and the like. By carrying out such control, the cradle 3becomes a system that does not supply power unless the host device 6 andthe PHD unit 1 are securely connected. Thus, with the cradle 3, forexample, even if only an external power source is connected, or even ifa cable which should not have been connected is erroneously connected,there is no risk that unusual power related circumstances would occur. Aswitch for turning external power (V_IN) from the power source jack 68on and off may be provided, and such control where that switch is turnedon when the voltage of the second USB power source pin 137 is detectedmay be performed.

The controller 138 can notify the user of the operative status of thecradle 3 by carrying out display control of the LED 84. For example, thecontroller 138 may turn on the LED 84 if the host device 6 and the PHDunit 1 are connected to the cradle 3. In addition, the controller 138may, for example, watch for a communication flag (a flag generated whendata is being transferred) generated by the USB/IDE conversion circuit133, and make the LED 84 blink if the host device 6 is writing orreading data.

In the PHD system that is configured as mentioned above and shown inFIG. 2, when the PHD unit 1 is mounted on the mounting section 60 of thecradle 3, first, the guide grooves 20 on the side of the PHD unit 1 andthe guide protrusions 48 on the side of the mounting section 60 areengaged with each other, and the PHD unit 1 is guided while beingmounted on the mounting section 60 of the cradle 3. Then, if the PHDunit 1 is mounted on the mounting section 60 of the cradle 3, theengagement protrusion 60 e on the side of the mounting section 60 isengaged with the engagement recess 14 on the side of the PHD unit 1, andthe first connector 10 on the side of the PHD unit 1 and the secondconnector 64 on the side of the adapter 2 are connected. Also, by havingthe engagement protrusion 73 b of the engagement member 73 engaged withthe engagement recess section 19 on the side of the PHD unit 1, a statewhere the PHD unit 1 is set in the mounting section 60 is suitablymaintained.

The first connector 10 on the side of the PHD unit 1 is attached withinthe plane of the opening 15 of the first housing 8 in a semi-fixed statewith some allowance for movement. On the other hand, the secondconnector 64 on the side of the mounting section 60 is attached in afixed state where it is engaged with the opening 71 of the secondhousing 61. Thus, in this PHD system, it is possible to suitably connectthe first connector 10 and the second connector 64 without positioningthem precisely, and damage to the connectors upon connecting can beprevented, while the connective reliability of the first connector 10and the second connector 64 can also be improved.

In addition, in this PHD system, as shown in FIG. 2, when the PHD unit 1is mounted on the mounting section 60 of the cradle 3, the firstdisplaying section 18 and the second displaying section 83 form acontinuous and linear displaying section between the first housing 8 andthe second housing 61, thereby making aesthetically superior displaypossible. Also, it helps to prevent erroneous connection when the PHDunit 1 is mounted on the mounting section 60 of the cradle 3, therebyimproving the ease of use.

This PHD system is electrically connected to, for example, a desktoppersonal computer 6, which is a host device, via the connection cable 7in a condition where the PHD unit 1 is mounted on the mounting section60 of the cradle 3. Thus, data is written to and read from the hostdevice 6.

In this PHD system, since power can be supplied to the PHD unit 1 froman external power source by having the plug of an AC adapter connectedto the power source jack 68, and not just from the host device 6 via thepower line of a USB compliant interface, even if the PHD unit 1 includesan HDD 9 of a high capacity, it is possible to stabilize the driving ofthis PHD unit 1, and prevent a drop in performance.

In addition, in this PHD system, by pressing the operation button 78 ofthe unlocking mechanism 77 in removing the PHD unit 1 from the mountingsection 60 of the cradle 3, the switching protrusion 79 a of theoperation member 79 operates the switch 81 on the first circuit board 62and cuts the electrical connection between the PHD unit 1 and the hostdevice 6 before the engagement between the engagement protrusion 73 b ofthe engagement member 73 and the engagement recess section 19 of the PHDunit 1 is undone. Thus, it is possible to protect the PHD unit 1.

As mentioned above, in the PHD systems shown in FIGS. 1 and 2, thecombination of the PHD unit 1 and the adapter 2 or the cradle 3 can bealtered easily depending on the usage. Also, in this PHD system, the PHDunit 1 can be easily replaced with respect to the adapter 2 or thecradle 3, and this PHD unit 1 itself can be carried freely. Also, thisPHD unit 1 may be miniaturized so that it can be handled with ease as aportable recording medium.

Although in the above-mentioned PHD system, a configuration is adoptedwhere the first connector 10 on the side of the PHD unit 1 issemi-fixed, and the second connectors 43 and 64 on the side of theadapter 2 and the cradle 3 are fixed, it is also possible to adopt aconfiguration where the first connector 10 on the side of the PHD unit 1is fixed, and the second connectors 43 and 64 on the side of the adapter2 and the cradle 3 are semi-fixed.

In other words, the first connector 10 is fixed in place by beingengaged with the opening 15 of the first housing 8 as mentioned above.On the other hand, the second connectors 43 and 63 are semi-fixed in theplanes of the openings 49 and 71, respectively, by being engaged withthe openings 49 and 71 of the second housings 40 and 61 with someallowance for movement as mentioned above.

Thus, in the PHD system, it is possible to suitably connect the firstconnector 10 and the second connectors 43 and 64 without positioningthem precisely, and prevent damage to the connectors upon connection,while at the same time improving the connective reliability between thefirst connector 10 and the second connectors 43 and 64.

In the present invention, the interface between the adapter 2 and thecradle 3 and the host devices 4 and 6 is not limited to a USB compliantinterface, and it is possible to adopt an interface that complies withIEEE (Institute of Electrical and Electronics Engineers) 1394, ATA/ATAPI(Advanced Technology Attachment/Packet Interface), SCSI (Small ComputerSystem Interface), PC Card and the like. Also, in the present invention,the interface between the adapter 2 and the cradle 3 and the hostdevices 4 and 6 is not limited to a wired interface using a connectioncable, and may be one that is connected through a transmission/receptionunit that complies with IEEE 802.11b (wireless LAN), Bluetooth (shortrange wireless communications) and the like.

Since the invention disclosed herein may be embodied in other specificforms without departing from the spirit or general characteristicsthereof, some of which forms have been indicated, the embodimentsdescribed herein are to be considered in all respects illustrative andnot restrictive. The scope of the invention is to be indicated by theappended claims, rather than by the foregoing description, and allchanges which come within the meaning and range of equivalents of theclaims are intended to be embraced therein.

1. A hard disk system that is used as an external storage apparatus of ahost device, comprising: a hard disk unit; and a conversion unit whichis attachable to and detachable from said hard disk unit, wherein saidhard disk unit includes: a hard disk for magnetically storing data; arecording/reading section for recording and reading data to and fromsaid hard disk; and a hard disk side interface section for having data,which is recorded on and read from said hard disk, inputted andoutputted to and from said conversion unit in a first transfer format,said conversion unit includes: a host interface section for transmittingand receiving data, which is recorded on and read from said hard disk,to and from said host device in a second transfer format; a conversionunit side interface section for having data, which is recorded on andread from said hard disk, inputted and outputted to and from said harddisk unit in said first transfer format; a transfer format conversionsection for carrying out transfer format conversion between said firsttransfer format and said second transfer format, and for carrying outdata transfer between said host interface section and said conversionunit side interface; and a power source section, said hard disk sideinterface section and said conversion unit side interface are, when saidhard disk unit and said conversion unit are connected, made capable oftransferring data between each other, and said power source sectionsupplies power to each section of said conversion unit when said harddisk unit and said conversion unit are connected.
 2. The hard disksystem according to claim 1, wherein said conversion unit has a firstterminal connected to a power line of said host interface section and asecond terminal connected to a power line of said conversion unit, and aconnection line, which connects said first terminal and said secondterminal when said conversion unit is connected, is provided in saidhard disk unit.
 3. The hard disk system according to claim 1, whereinsaid conversion unit has a DC input terminal to which direct currentpower is inputted from an external power source, and said power sourcesection supplies said direct current power inputted from said DC inputterminal to said hard disk unit.
 4. A hard disk system that is used asan external storage apparatus of a host device, comprising: a hard diskunit; and a conversion unit which is attachable to and detachable fromsaid hard disk unit, wherein said hard disk unit includes: a hard diskfor magnetically storing data; a recording/reading section for recordingand reading data to and from said hard disk; and a hard disk sideinterface section for having data, which is recorded on and read fromsaid hard disk, inputted and outputted to and from said conversion unitin a first transfer format, said conversion unit includes: a hostinterface section for transmitting and receiving data, which is recordedon and read from said hard disk, to and from said host device in asecond transfer format; a conversion unit side interface section forhaving the data, which is recorded on and read from said hard disk,inputted and outputted to and from said hard disk unit in said firsttransfer format; a transfer format conversion section for carrying outtransfer format conversion between said first transfer format and saidsecond transfer format, and for carrying out data transfer between saidhost interface section and said conversion unit side interface; a powersource section; and a secondary battery, said hard disk side interfacesection and said conversion unit side interface are, when said hard diskunit and said conversion unit are connected, made capable oftransferring data between each other, and when said hard disk unit andsaid conversion unit are connected, said power source section suppliescombined power of power of a power line of said host interface sectionand power of said secondary battery to said hard disk unit.
 5. The harddisk system according to claim 4, wherein said power source sectionsupplies power to each section of said conversion unit when said harddisk unit and said conversion unit are connected.
 6. The hard disksystem according to claim 5, wherein said conversion unit includes afirst terminal connected to said power line of said host interfacesection and a second terminal connected to a power line of theconversion unit, and a connection line, which connects said firstterminal and said second terminal when said conversion unit isconnected, is provided in said hard disk unit.
 7. The hard disk systemaccording to claim 4, wherein said power source section includes avoltage generating circuit for generating a stable voltage regardless ofload, and said voltage generating circuit generates a voltage based onsaid combined power, and supplies the generated voltage to said harddisk unit.
 8. The hard disk system according to claim 7, wherein saidconversion unit includes a DC input terminal to which direct currentpower from an external power source is inputted, and said power sourcesection supplies the direct current power, which is inputted from saidDC input terminal, to said voltage generating circuit when in a firstmode in which the direct current power is inputted from said DC inputterminal, and supplies the combined electric power of the power of saidpower line of said host interface section and the power of saidsecondary battery to said voltage generating circuit when in a secondmode in which the direct current power is not inputted from said DCinput terminal.
 9. The hard disk system according to claim 8, wherein,when in said first mode, said power source section supplies the directcurrent power inputted from said DC input terminal to said secondarybattery and charges said secondary battery.
 10. The hard disk systemaccording to claim 4, wherein said conversion unit includes atemperature sensor for detecting the temperature of said secondarybattery, and said power source section does not charge said secondarybattery if the temperature of said secondary battery detected by saidtemperature sensor becomes higher than a predetermined temperature. 11.The hard disk system according to claim 4, wherein said conversion unitincludes a temperature sensor for detecting the temperature of saidsecondary battery, and said power source section stops supplying powerto said hard disk unit if the temperature of said secondary batterydetected by said temperature sensor becomes higher than a predeterminedtemperature.
 12. The hard disk system according to claim 11, whereinsaid power source section detects a point in time when data transfer isnot performed between said host device and said hard disk unit, andstops supplying power to said hard disk unit at said point.
 13. The harddisk system according to claim 7, wherein said conversion unit has acapacity detector for detecting the power capacity of said secondarybattery, and said power source section sends a warning to said hostdevice through said host interface section if the capacity detected bysaid capacity detector falls below a first value.
 14. The hard disksystem according to claim 13, wherein said power source section stopssupplying power to said hard disk unit at a time when data transfer isnot performed between said host device and said hard disk unit if thecapacity detected by said capacity detector falls below a second valuethat is smaller than said first value.
 15. The hard disk systemaccording to claim 14, wherein said power source section detects a pointin time when data transfer is not performed between said host device andsaid hard disk unit, and stops supplying power to said hard disk unit atsaid point.